The present invention relates to a seat for vehicles which is inclined to protect an occupant at the time of collision of a vehicle.
Such a seat for vehicles is known from JP-A-06-183292. In this seat for vehicles, a front section of a seat portion is pivotally attached to a horizontal shaft, and a rear section of the seat portion is supported to an actuator rod and pulled down by a coiled spring. When a vehicle collides with an object and a signal greater than a predetermined value is transmitted from a collision sensor, the actuator operates through a control unit to pull back the actuator rod. Because the supporting of the rear section of the seat portion is eliminated as a result, the rear section of the seat portion is pulled down by the coiled spring so that the seat rotates around the horizontal shaft so as to be inclined. Accordingly, the occupant assumes the posture of holding his/her knees in his/her arms so that the occupant is protected from the shock load due to the collision.
In the occupant protecting system in such a seat for vehicles, a relatively large amount of time is required for completion of inclination of the seat after the collision due to the necessity of including the response time of a collision sensor, the arithmetic operation time of a control unit, the operating time of an actuator, the inclining operation time of the seat, etc. Accordingly, it is difficult to incline the seat in a period (tens of milliseconds) from a point of time when the vehicle collides with an object to a point of time when the occupant collides with front glass of the vehicle.
Furthermore, the occupant protecting system is complex and very expensive in structure because the system requires a collision sensor, a control unit, two actuators and coiled springs.